From Concept to Context: Evaluating International Sponge City Practices for Türkiye's Urban Future

ARCHITECTURAL SCIENCES AND SUSTAINABLE APPROACHES: URBAN RESILIENCE Editors Prof. Dr. Ömer ATABEYOĞLU Prof. Dr. Ertan DÜZGÜNEŞ October 15, 2025 Copyright © 2025 by İKSAD publishing house All rights reserved. No part of this publication may be reproduced, distributed or transmitted in any form or by any means, including photocopying, recording or other electronic or mechanical methods, without the prior written permission of the publisher, except in the case of brief quotations embodied in critical reviews and certain other noncommercial uses permitted by copyright law. Institution of Economic Development and Social Researches (The Licence Number of Publicator: 2014/31220) TÜRKİYE TR: +90 342 606 06 75 USA: +1 631 685 0 853 E mail: [email protected] www.iksadyayinevi.com It is responsibility of the author to abide by the publishing ethics rules. Iksad Publications – 2025© Architectural Sciences and Sustainable Approaches: Urban Resilience ISBN: 978-625-378-337-2 Cover Design: Prof. Dr. Ertan DÜZGÜNEŞ October 15, 2025 Ankara / Türkiye Size = 16x24 cm PREFACE Dear Professors and Colleagues, We are pleased bring to life that Architectural Sciences and Sustainable Approaches: Urban Resilience, which was published as an e-book by IKSAD Publishing House with the editors Prof. Dr. Ömer ATABEYOĞLU and Prof. Dr. Ertan DÜZGÜNEŞ. This book project, entitled “Architectural Sciences and Sustainable Approaches: Urban Resilience,” aims to address sustainability-oriented approaches to urban resilience from theoretical, methodological, and practical perspectives. The volume seeks to establish a multi-layered platform of discussion, ranging from the scale of individual buildings to the entirety of the urban fabric. Within this framework, it welcomes contributions from scholars and researchers working in architecture, urban design, landscape architecture, urban and regional planning, environmental engineering, and related disciplines. With the valuable contributions of our chapter authors working in the professional disciplines of landscape architecture, architecture, city and regional planning, urban design and sustainability, we have completed Architectural Sciences and Sustainable Approaches: Urban Resilience book study has been completed with 24 book chapters. We would like to thank you, our esteemed authors, for their contributions to the preparation of the book. We would also like to thank the editorial board and IKSAD Publishing House. We wish to continue this process we have started in the coming years. In addition, we would like to express our sincere appreciation to Prof. Dr. Atila GÜL, the book coordinator of IKSAD Publishing House, for his guidance and support throughout the publication process. We hope that our book ‘Architectural Sciences and Sustainable Approaches: Urban Resilience’ will be helpful to the readers. Best regards. 15.10.2025 EDITORS Prof. Dr. Ömer ATABEYOĞLU Prof. Dr. Ertan DÜZGÜNEŞ EDITORS Prof. Dr. Ömer ATABEYOĞLU Prof. Dr. Ertan DÜZGÜNEŞ AUTHORS The authors were listed in alphabetical order Alper ÇABUK Ayça GÜLTEN Ayşe ÖZYETGİN ALTUN Ayşe Özge ŞİMŞEK SOYSAL Ayşegül TANRIVERDİ KAYA Demet EROL Deniz DEMİRARSLAN Ebru Vesile ÖCALIR Eda ŞENTÜRK Elif Kübra ÖZTÜRK Emine BAYDAN Esra KESKİN Feran AŞUR Feyza Sena ŞENOCAK Filiz KARAKUŞ Furkan AKDEMİR Gencay ÇUBUK Gülşah BİLGE ÖZTÜRK Halil DUYMUŞ Hamza ALTAŞ Hande AKARCA İnci OLGUN Kemal Mert ÇUBUKÇU Kumru ÇILGIN Mehmet Akif IRMAK Mehmet Emin DAŞ Mehtap ÖZENEN KAVLAK Merve ALICI AKA Mesut GÜZEL Muhammed Akif AÇIKGÖZ Muhammed Emir GÖRAL Murat YEŞİL Olcay Türkan YURDUGÜZEL Özge DÜZGÜN EREKİNCİ Pervin YEŞİL Rabia Nurefsan ACIKGOZ Sedef ŞENDOĞDU Seher Simay KUŞOĞLU Serim DİNÇ Sevilay YILDIZ Sinem SEYHAN Şevval ERGİNDOĞAN Şuheda ALTUNOK Temuçin Göktürk SEYHAN Tuba Nur OLĞUN Tuna BATUHAN Ufuk Teoman AKSOY Yusuf Eminoğlu REVIEWER LIST The authors were listed in alphabetical order Aslıhan TIRNAKÇI Nevşehir Hacı Bektaş Veli University Atila GÜL Süleyman Demirel University Ayşe Kalaycı ÖNAÇ İzmir Katip Çelebi University Bige ŞİMŞEK İLHAN İstanbul Medipol University Burcu YILMAZEL Eskişehir Technical University Eda KOÇAK Siirt University Ekrem BAHADIR Ankara Yıldırım Beyazıt University Elif KUTAY KARAÇOR İstanbul Technical University Hakan ARSLAN Ondokuz Mayıs University Hilal TURGUT Karadeniz Technical University Meliha AKLIBAŞINDA Nevşehir Hacı Bektaş Veli University Murat AKTEN Süleyman Demirel University Nihan Sümeyye GÜNDOĞDU Atlas University Okan Murat DEDE Amasya University Ömer Lütfü ÇORBACI Recep Tayyip Erdoğan University Selcen Nur Erikci Çelik Beykoz University Sibel AKTEN Isparta Unıversıty Of Applıed Scıences Sinem ÖZDEDE Pamukkale University Şeyma ŞENGÜR Ordu University Turgut KALAY Kütahya Dumlupınar University Tendü Hilal GÖKTUĞ Aydın Adnan Menderes University 2 1. Introduction The rapid pace of urbanisation, the intensifying impacts of climate change, and the inadequacy of existing infrastructure systems have significantly increased the risks of flooding, particularly in cities experiencing heavy rainfall (Guan, Wang & Xiao, 2021). Under these conditions, redefining the relationship between cities and water and enhancing urban resilience through nature-based solutions has become increasingly critical. In this context, the sponge city approach has emerged as an innovative and integrated model for sustainable urban water management (Sun, Deng, Pan, Chiang, Sable & Shah, 2020). Rather than prioritising the rapid drainage of stormwater from urban surfaces, the sponge city model emphasises the retention, infiltration, groundwater recharge, and reuse of rainwater. Integrated into the urban fabric through nature-based solutions such as permeable landscapes, green roofs, rain gardens, and open drainage infrastructure, this system provides both hydraulic and ecological functions (Chan, Griffiths, Higgitt, Xu, Zhu, Tang, Xu, Yuyao & Thorne, 2018; Guan et al., 2021; Qiao, Liao & Randrup, 2020). The sponge city concept was first officially introduced into China’s policy agenda in 2013, primarily to reduce urban flood risks, improve water quality, and restore urban ecosystems (Zevenbergen, Fu & Pathirana, 2018). This approach treats water not as a threat but as a resource that must be managed and recovered, aiming to align the urban water cycle with natural processes (Yu, 2012; Cosier & Shen, 2009). Components such as rain gardens, permeable surfaces, green roofs, and biofiltration zones constitute the core elements of sponge cities (Xiang, Liu, Shao, Mei & Zhou, 2019). In addressing challenges such as floods and droughts, sponge 3 city initiatives contribute to the creation of more resilient, sustainable, and livable cities while preserving ecosystem services (Esbah, 2021). While some studies in the literature focus on the hydraulic performance and engineering aspects of sponge city systems (Hou, Guo, Wang, Li, Xue, Liu & Zeng, 2020; Jia, Wang, Zhen, Clar & Yu, 2017; Liv et al., 2017; Xia, Zhang, Xiong, He, Wang, 2017), a substantial portion of the research highlights the multidimensional impacts of the model. Sponge city practices have been evaluated across various domains, including urban planning (Chan et al., 2018; Fang, 2020; Wei, Jiazhuo, Han, Chen, Chunyang, Lian & Jin, 2017), landscape architecture (Jiang, Hua & Shao, 2022; Shi, Li, Shi, Xiu & Chu, 2021; Zhang, 2017), community participation (Chan, Lu, Zhu, Balzan, Pezzoli, Johnson, Zhu, Ruan, Luo, Li & Xu, 2023; Wang, Cai, Zuo, Bartsch & Huang, 2021), policy development (Guo, 2023; Tu & Tian, 2015), and economic sustainability (Liang, 2018; Ma, Liu & Wang, 2023; Zhu, Xu, Yin, Xu, Wu & Jia, 2022). For instance, Li, Zhang & Xie (2019) emphasise that sponge cities not only improve water management but also offer environmental and social benefits such as mitigating the urban heat island effect, supporting biodiversity, and enhancing quality of life. Conversely, Chan et al. (2018) stress the importance of local contextual factors, governance models, and levels of public participation in the successful implementation of sponge city practices. The application of sponge city models varies across countries depending on climatic, cultural, and institutional contexts. While China has integrated the model into large-scale national urban transformation projects, European countries such as Germany, the Netherlands, and Denmark have 4 incorporated similar practices into their existing green infrastructure policies (Walker, Ashley, Nowell, Gersonius & Evans, 2012). For example, the “Water Squares” initiative in Rotterdam combines public spaces with temporary water storage functions, while Copenhagen integrates flood risk reduction with multifunctional water management strategies (Liao, 2012). These examples demonstrate the adaptability of the sponge city model to local needs and its potential as a flexible and context-sensitive approach. In the context of Türkiye, studies on sponge cities have typically focused on themes such as climate change, flood risk, and urbanisation (Bayramoğlu & Seyhan, 2022; Kırmızıbayrak, Demircan & Irmak, 2024; Meral, 2025; Tuğaç, 2022; Yörüklü, 2021). The pressures of rapid urban growth, infrastructure deficiencies, and the increasing frequency of flash floods underscore the urgency of adopting this approach in Türkiye (Atar, 2023). Recent flood events in major cities, such as Istanbul, Ankara, and Izmir, have highlighted the inadequacy of current infrastructure in addressing climate-induced disasters (Limoncu & Bayülgen, 2005). However, national policy documents such as the 2023–2027 Strategic Plan and the Climate Change Adaptation Strategy reference green infrastructure and nature-based solutions; a comprehensive framework for implementing these approaches has yet to be established (Republic of Türkiye Ministry of Environment, Urbanisation and Climate Change, 2022). This study aims to assess the potential of the sponge city approach within Türkiye’s urban water management policies by examining the concept’s theoretical foundations and international implementation practices. The chapter first outlines the core principles and evolution of the sponge city 5 model, followed by a comparative analysis of practices in China, Europe, and other regions. It concludes with a context-specific model proposal for adapting sponge city strategies to Türkiye’s urban planning landscape. 2. Theoretical Framework of the Sponge City Approach 2.1. The Concept of Sponge City and Its Theoretical Foundations One of the major challenges cities face in the 21st century is the disruption of the natural water cycle due to increasing urbanisation pressures. This disruption leads to a range of multifaceted consequences, including heightened flood risks, water scarcity, ecological imbalances, and infrastructural deficiencies (Zha, Luo, Zhu, Wang, Lyu, Zhou, ... & Wang, 2021). In particular, the rise in sudden and intense precipitation events associated with climate change has exacerbated urban flooding in areas dominated by impervious surfaces, straining the resilience capacities of cities. The sponge city approach has emerged in this context as a contemporary urban water management model that aims to reconfigure the relationship between cities and water through a nature-based paradigm (Sun et al., 2020). Its core principle is not the rapid discharge of stormwater, but its on-site retention, filtration, and reuse (Yin, Xu, Jia, Yang, Sun, Wang & Liu, 2022). This approach views water not as a threat, but as a fundamental component of the urban ecosystem. Sponge cities are envisioned as ecological systems that can “absorb, retain, process, and release water when needed” (Li et al., 2019). Through large-scale Sustainable Drainage Systems (SuDS), this model mimics the natural water cycle by absorbing, storing, and reusing stormwater. Unlike the conventional approach, where stormwater is rapidly transported via expanding pipe networks to watercourses, the 6 sponge city model emphasises source control through nature-based techniques (Green Blue Urban, 2025). As a result, it fundamentally transforms both the planning logic and water management practices of urban landscapes. The institutionalisation of the sponge city model began in China in 2013, when it was integrated into national urban development policies. However, its intellectual roots trace back to earlier approaches such as Low Impact Development (LID) and Green Infrastructure, which emerged in the late 20th century (Chan et al., 2018). Central to the sponge city paradigm are principles such as the reconstruction of the hydrological cycle within urban environments, biomimicry of natural processes, and the restructuring of the human-nature interface in cities. Accordingly, sponge cities are not merely technical infrastructure projects but comprehensive urban strategies that require rethinking landscape design, spatial planning principles, and modes of civic participation (Nguyen, Ngo, Guo, Wang, Ren, Li, Ding & Liang, 2019). This approach rests upon a multi-layered theoretical foundation informed by diverse disciplines. It draws from the literature of ecological modernisation, systems theory, urban ecology, and resilience. The theory of ecological modernisation emphasises the role of technological innovation, planning reform, and development aligned with ecological principles in addressing environmental challenges (Mol & Sonnenfeld, 2000). In this regard, sponge cities are positioned as modern planning strategies that integrate ecological sustainability into urban infrastructure. By reducing environmental risks through nature-based solutions and 7 enhancing the quality of life, sponge cities directly align with the objectives of this theory. From an urban ecology perspective, cities are understood not only as human-made constructs but as bio-physical systems shaped by interactions between water, soil, air, and living organisms. The sponge city model operationalises this perspective by ensuring the cyclical management of surface water, rainfall, and groundwater as components of the urban ecosystem (Pickett, Cadenasso & Grove, 2004). Systems theory and the adaptive governance of urban systems offer valuable conceptual tools for understanding the complex, multi-actor structures that define sponge cities. When cities are conceptualised as interwoven systems composed of infrastructure, ecology, economy, and society, the need for integrated, flexible, and adaptive responses becomes apparent. Sponge cities reflect this by reimagining cities not merely as conduits for water but as dynamic, regenerative systems capable of managing water intelligently (Chester & Allenby, 2019). The concept of resilience is another foundational pillar of the sponge city model. In light of the growing intensity of climate-related hazards, such as floods, droughts, and extreme weather, sponge cities serve not only as tools for risk mitigation but also as strategic frameworks for urban adaptation and climate resilience (Ahern, 2011). The sponge city model consists of a wide array of technical and planning components. These include the expansion of permeable surfaces, green roofs and walls, bioswales, rain gardens, rainwater harvesting systems, water-retentive parks, green corridors, and open-channel drainage infrastructure (Zhou, 2014). These systems can be implemented at both 8 central (e.g., watershed-level) and local (e.g., household-level) scales. This multi-scalar structure enhances the model’s adaptive capacity, setting it apart from conventional water management systems. Decentralised, nature-compatible, and contextually flexible solutions-such as water retention, delay, filtration, and reuse-constitute the core operational principles of sponge cities (Chan et al., 2018). By moving beyond traditional engineering paradigms, the sponge city model integrates nature-based infrastructure with participatory governance mechanisms and social awareness components. For the model to be implemented effectively, it requires the coordinated functioning of its physical, administrative, ecological, and societal dimensions (Table 1). Table 1. Core components of the sponge city model (Guan et al., 2021; Luan, Yin, Xu, Wang, Yang, Zhang & Tang, 2019; Nguyen, Ngo, Guo & Wang, 2020; Xiang et al., 2019; Yang, Xu & Shi, 2017; Zhao, Gao & Zuo, 2019) Component Type Subcomponents Description Physical Green roofs Permeable pavements Rain gardens Water-retaining parks Open drainage systems Nature-based physical infrastructure elements that enable the absorption and storage of rainwater. Managerial Integrated urban water management Disaster risk management Institutional cooperation Financing and incentive models Strategic governance and interagency coordination in planning, regulation, and resource utilisation processes. Ecological Ecosystem services Biodiversity support Soil permeability Microclimate regulation Support for the natural water cycle through the strengthening of urban ecosystems and the enhancement of climate adaptation capacity. Social Participatory planning Community awareness Educational programs Urban quality of life Public acceptance of the sponge city approach ensures sustainability and promotes social inclusiveness. 9 Physical components such as green roofs, permeable surfaces, and open drainage systems enable effective stormwater management through nature-based solutions. However, these structural interventions yield sustainable outcomes only when supported by administrative coordination, ecological balance, and public participation. The components presented in Table 1 demonstrate that the sponge city model must be integrated not only technically but also in managerial, environmental, and social dimensions. Such a holistic structure aims to enhance urban resilience against challenges such as climate change, flood risk, and water scarcity. 2.2. Thematic Dimensions of Sponge City Practices The sponge city approach is not merely a physical infrastructure design, but a multidimensional proposal for transforming urban systems. Within this framework, sponge city practices can be analysed under four main thematic dimensions: urban planning, water management and climate change adaptation, public participation and governance, and ecological and technological components. This thematic structure enables a comprehensive evaluation of the sponge city model, encompassing not only its technical infrastructure but also its administrative and social dimensions. First, in the context of urban planning, the sponge city approach is directly related to decisions on site selection, land use, and the planning of open and green spaces. While conventional planning paradigms often increase the prevalence of impervious surfaces, sponge city planning promotes a morphological structure that protects the natural water cycle and manages water at its source (Ma et al., 2023). In this regard, physical strategies such as permeable surfaces, multifunctional parks, and stormwater corridors are 10 integrated into land use plans, and new planning tools are developed in alignment with the topographic and hydrological characteristics of urban areas (Chan et al., 2018). This makes the spatial integration of sponge city principles particularly imperative in rapidly urbanising regions. Second, water management and climate change adaptation, central pillars of the sponge city model, are critical components that determine the model’s sustainability and functionality. Sponge city practices rely on integrated processes such as on-site water retention, filtration, and reuse, rather than traditional drainage systems. The underlying objective is to redefine rainwater as a “resource” rather than a “waste” product. Additionally, these practices provide multiple benefits, including flood risk reduction during extreme rainfall events, mitigation of the urban heat island effect, and the replenishment of groundwater resources (Qiao et al., 2023). As such, sponge cities have become key instruments in climate change adaptation policies, especially in areas such as disaster risk management, drought mitigation, and microclimate regulation. Third, the dimension of public participation and governance represents the social foundation for the success of sponge city initiatives. The effective operation of technical infrastructure depends not only on engineering solutions but also on the inclusion of the public in decision-making processes, the incorporation of local knowledge, and the implementation of awareness-raising practices (Chan et al., 2018). Participatory planning enables micro-scale interventions at the neighbourhood level, facilitating the development of solutions that are more responsive to local needs. Moreover, educating and engaging citizens on individual practices, such 11 as water conservation, the use of permeable materials, and rooftop gardens, is essential for widespread behavioural change and long-term success. Ultimately, both ecological and technological components support the nature-based structure of sponge cities, thereby enhancing their overall performance. The sponge city approach actively utilises ecosystem services, such as natural filtration, carbon sequestration, and biodiversity support, while also integrating innovative technologies to strengthen monitoring, control, and assessment mechanisms. For example, sensorbased water level monitoring systems, smart drainage infrastructure, and satellite-assisted land permeability mapping technologies enhance the efficiency of sponge city infrastructure and optimise maintenance processes (Zevenbergen et al., 2018). From an ecological perspective, elements such as green roofs, bio-retention ponds, and urban wetlands function not only as water-absorbing systems but also as integral parts of urban ecology. These four thematic dimensions demonstrate that sponge city practices are not merely physical interventions, but also governance, ecological, and societal transformation strategies 3. Advantages and Challenges of the Sponge City Approach The sponge city approach stands out as an innovative model offering comprehensive solutions to contemporary urbanisation challenges through its multifaceted environmental, social, and economic benefits. This model makes a significant contribution to addressing critical urban issues, including climate change, flood risks, and the sustainable management of water resources. However, despite its potential, the implementation of sponge cities is not without challenges; it faces various technical, institutional, and societal obstacles. Therefore, for this approach to be 18 managing water at its source, and integrating green-blue infrastructure networks (MoEUCC, 2023). Similarly, the Rainwater Harvesting Guide Document (2022) is regarded as an initial step toward the technical and structural transformation required to recognise rainwater as a valuable resource rather than as waste. Meanwhile, water policies in Türkiye have evolved in parallel with international developments. Influenced by global frameworks such as the Rio Summit (1992), World Water Forums (1997–present), and the EU Water Framework Directive (2000/60/EC), Türkiye has adopted a basinbased and multi-stakeholder approach to water governance. Public institutions such as the Ministry of Agriculture and Forestry, the General Directorate of State Hydraulic Works (DSİ), and the General Directorate of Water Management play key roles in water governance. At the same time, think tanks like SUEN contribute to policy development. Through basin-level and provincial coordination mechanisms, localised water governance is increasingly feasible. Despite these advances, integration of water policy with urban planning and design remains limited in Türkiye. Nature-based solutions are not yet clearly defined within the current legal framework, and the long-pending Water Law Draft, which has been under development since the 1990s, has yet to be enacted (Tunçay, 2022). This legal gap represents a critical opportunity to establish a robust regulatory foundation for implementing the sponge city model. According to the Falkenmark Index, Türkiye is a water-stressed country. While the annual per capita water availability was 1,652 m³ in 2000, this figure declined to 1,346 m³ in 2020 and is projected to fall to 1,120 m³ by 19 2030 (ATB, 2021). This trend highlights the urgent need to manage both rainwater and greywater as valuable urban resources through nature-based solutions (Esbah, 2021). In alignment with this necessity, TARAP (2022) recommends adopting risk-based, preventive, and nature-based strategies in urban planning. Nevertheless, current technical regulations are still heavily reliant on grey infrastructure solutions. Legislative documents, such as the Regulation on Rainwater Collection, Storage, and Discharge Systems (2017) and the Regulation on Wastewater Collection and Disposal Systems (2017), do not adequately incorporate nature-based approaches. Although a 2021 amendment to the Zoning Regulation made rainwater harvesting systems mandatory for parcels over 2,000 m², broader dissemination of these systems and their integration with green infrastructure remain necessary. Moreover, protective regulations for urban streambeds under the İSKİ Law have proven insufficient. For example, the reduction of stream buffer zones from 100 meters to 10 meters in 2013 and the physical alteration of 64% of streambeds in Istanbul necessitate a re-evaluation of current protection strategies (Tunçay, 2022). In summary, while strategic and institutional developments in Türkiye increasingly support the transition to sponge cities, updating legal frameworks, integrating nature-based solutions into planning systems, and strengthening the implementation capacity of local governments remain essential. 5.2. Urban Water Management in Türkiye and the Need for the Sponge City Approach Türkiye is among the countries where the impacts of climate change are being experienced with increasing frequency and severity, while rapid 20 urbanisation continues to exert growing pressure on the natural water cycle. In recent years, particularly in major metropolitan areas, sudden and intense rainfall events have highlighted the inadequacy of existing urban infrastructure in coping with such extreme weather conditions. The increasing proportion of impervious surfaces, urban development in streambeds, insufficient drainage systems, and disruptions to the natural flow of water have collectively rendered cities highly vulnerable to flooding with almost every rainfall event. This situation not only causes physical damage but also leads to loss of life, destruction of infrastructure, economic losses, and heightened social vulnerability. Current urbanisation and water management policies are insufficient to mitigate these risks. Thus, there is a pressing need for a new paradigm in which water is regarded not as a threat, but as a natural asset that must be managed sustainably. Within this context, the sponge city model, centred around nature-based solutions and on-site water management, offers a strategic alternative for building flood-resilient cities in Türkiye. To better understand the urgency of this need, it is necessary to examine recent flood and inundation events that have occurred across Türkiye in recent years (Figure 1). 21 Figure 1. Provincial Distribution of Flood and Inundation Events in Türkiye (AFAD, 2018) In Türkiye, floods and inundations predominantly occur as a result of the overflow of rivers and streambeds, typically triggered by natural phenomena such as sudden and intense rainfall or snowmelt. However, human-induced interventions-particularly the misuse of stream corridors through unplanned urbanisation, construction, landfilling activities, and alteration of natural watercourses-significantly exacerbate flood risks. In mountainous regions, floods may also lead to secondary hazards such as landslides, posing serious threats to settlements located on mountain slopes. Additionally, though less frequent, hydrological events such as lake overflows driven by atmospheric conditions or tsunamis in coastal zones can also constitute localised flood threats. An analysis of the spatial distribution of flood and inundation events since 1950 indicates that provinces such as Erzurum, Sivas, Van, and Bitlis are among the most affected. In contrast, incidents in provinces like Uşak, Kilis, and Yalova have been relatively rare. Overall, a geographic trend reveals a higher 22 frequency of flood events toward the eastern and northern regions of the country. 5.3. A Contextualised Sponge City Model for Türkiye In recent years, the combination of sudden and intense precipitation events, inadequate infrastructure systems, and rapid, unplanned urbanisation has significantly increased flood risk in Türkiye-particularly in major metropolitan areas, while simultaneously undermining urban resilience capacities. Urban flooding incidents in cities such as Istanbul, Ankara, Izmir, and Bursa are not solely the result of infrastructural deficiencies; they are also driven by the expansion of impervious surfaces and the disruption of the natural water cycle. As a nature-based and sustainable approach capable of addressing these challenges, the sponge city model holds strategic potential for integration into Türkiye’s urban water management policies. However, the model’s applicability must be assessed within a multi-layered framework involving local government capacities, spatial planning practices, public awareness levels, and legalinstitutional compatibility. The proposed sponge city model for Türkiye should be structured around three core dimensions: spatial and morphological adaptation, governance integration, and community engagement and awareness. First, concerning spatial and morphological adaptation, sponge city interventions must be designed in harmony with local topography, climate conditions, soil characteristics, and existing infrastructure systems. In this context, areas with high rainfall levels, such as the Black Sea coastal region, as well as metropolitan zones and rapidly growing secondary cities (e.g., Kocaeli, Antalya, Gaziantep), may be designated as priority pilot 23 areas. In these locations, increasing permeable surface coverage, developing water-retentive parks, and integrating open drainage systems into urban design are essential. Sponge infrastructure criteria should be incorporated into urban regeneration projects, and mandatory standards for sponge city components should be introduced in zoning and land-use planning processes to ensure institutionalisation. Second, governance integration is crucial to the success of sponge city applications, particularly given Türkiye's fragmented and multi-actor institutional landscape. Currently, stormwater management, infrastructure services, green space planning, and disaster risk reduction are carried out by different public institutions with limited horizontal and vertical coordination. Therefore, a centralised strategic framework should be developed to guide the planning and implementation of sponge city initiatives at the local level. Institutional cooperation protocols must be established among the Ministry of Environment, Urbanisation and Climate Change, local municipalities, water and sewerage authorities, and disaster response agencies such as AFAD. Furthermore, enhancing the technical capacities of municipalities, introducing financial incentive mechanisms, and establishing dedicated funding for sponge infrastructure investments would facilitate the dissemination of the model. Third, the applicability of the sponge city model in Türkiye must also be approached from a societal perspective, just as a technical or administrative issue. The lack of public awareness regarding rainwater management, green infrastructure, and the role of permeable surfaces may hinder the social acceptance and long-term sustainability of nature-based practices. Accordingly, public education campaigns, neighbourhood-scale 24 participatory design workshops, and awareness programs focused on sustainable water use should be considered integral components of the model. Universities, professional chambers, and civil society organisations should be actively involved in the process to foster knowledge exchange between scientific research and local experience. The proposed sponge city model, which integrates all these components, holds both risk-reduction and resource-conversion potential for Türkiye. Transforming rainwater from a waste product into a valuable element of an integrated urban water cycle; reimagining green infrastructure as not only aesthetic but also functional and resilience-enhancing; and integrating planning, infrastructure, and governance into a multi-level, coordinated system constitute the foundational principles of this model. It should not only be tailored for large metropolitan areas but also offer scalable, flexible, and context-sensitive solutions for small and medium-sized cities experiencing water stress. For the successful implementation of sponge city practices in Türkiye, pilot cities should be selected based on diverse climate zones, risk profiles, and socioeconomic conditions (Table 3). Table 3. Proposed cities for pilot sponge city implementation in Türkiye Country Justification Implementation Priority İstanbul High urban density, infrastructure stress, and elevated flood risk Permeable surfaces, rainwater harvesting, and green roofs Trabzon Black Sea climate, sudden precipitation events, and landslide susceptibility Vertical water management and open-channel drainage systems Konya Arid climate conditions and declining groundwater levels Water-retentive open spaces, harvesting, and reuse strategies Antalya Tourism-driven pressure, water scarcity, and coastal vulnerability Sustainable water planning through nature-based solutions 25 Gaziantep Rapid urban growth, urban heat island effect, and unregulated development Integration of green infrastructure and microclimate regulation Eskişehir Planned urban structure and a high concentration of student population Community engagement and campus-scale sponge city interventions The successful implementation of the sponge city approach in Türkiye depends not only on physical infrastructure investments but also on aligning existing planning, permitting, and infrastructure regulations with this new paradigm. In this regard, a comprehensive restructuring of legal, administrative, and institutional frameworks is essential. First, integrating sponge city principles into urban planning processes would facilitate a transformative shift in spatial decision-making. It is crucial to establish minimum permeability standards in master and detailed development plans and to incorporate parks, green areas, and neighbourhood-scale rainwater collection zones as core planning elements. Furthermore, the mandatory inclusion of water-retentive infrastructure in zoning plan notes would guide local planning practices in line with the objectives of sponge cities. Such regulatory amendments should be prioritised, particularly in areas at high risk of natural disasters. Second, revising building permit procedures to include rainwater management criteria would ensure that individual buildings contribute to the broader sponge city system. The promotion, and in certain zones, the requirement of interventions such as green roofs, permeable paving materials, and rainwater harvesting tanks in new constructions would help scale up sustainable water management at the building level. These practices should be integrated into the building inspection system through 26 enforceable technical standards, and municipalities should be granted both inspection authority and support mechanisms in this regard. Third, updates to existing stormwater and infrastructure legislation are required to standardise and expand technical implementation. While current regulations constitute important steps in urban water management, they do not yet comprehensively reflect the core principles of the sponge city model. Therefore, more detailed legal frameworks are needed for practices such as permeable surfaces, nature-based solutions, openchannel systems, and rainwater harvesting. Additionally, updating standardised technical drawings and implementation catalogues used in infrastructure projects would further reinforce implementation capacity. Another key area of reform involves aligning urban transformation legislation with the principles of sponge cities. Urban renewal projects offer a unique opportunity to redesign the physical environment. In this context, it is imperative to incorporate nature-based solutions and urban water management components into compulsory transformation initiatives in disaster-prone areas. The integration of sponge infrastructure into urban renewal would serve the dual purpose of enhancing environmental sustainability and reducing disaster risks. Furthermore, the establishment of financial and administrative incentive mechanisms is a necessary complement to legal reform and a crucial element for implementation. Central government support programs targeting municipalities that implement sponge city projects should be structured through dedicated financing channels, such as those managed by İLBANK or the Turkish Environment Agency. They may include lowinterest loans, grants, or earmarked funds. Legal provisions that support 27 such financial incentives would directly enhance the implementation capacity of local governments. In parallel, tax regulations and publicprivate partnership models should be developed to encourage private sector investment in sponge city initiatives. Finally, a robust legal infrastructure is also necessary in areas such as education, capacity building, and data governance. Certified training programs for municipal staff and relevant professional groups should be made mandatory by regulation to ensure the quality of implementation. Intelligent infrastructure systems that facilitate the monitoring of variables such as precipitation, surface runoff, and groundwater levels should be promoted. Data sharing should be conducted via open-data digital platforms to ensure transparency and coordination. In conclusion, the sponge city model to be developed for Türkiye must serve not only as a tool for climate change adaptation, but also as an integrated strategy for sustainable urbanisation, disaster risk reduction, water resource conservation, and enhancement of urban quality of life. When considered alongside the proposed conceptual framework, pilot implementation areas, and corresponding legal and institutional arrangements, the practical feasibility of the model would be significantly strengthened. 6. Conclusion and Policy Recommendations In today’s urban landscape, where multidimensional challenges such as rapid urbanisation, climate change, natural disaster risk, and resource scarcity increasingly intersect, strengthening the environmental, social, and infrastructural resilience of cities has become imperative. This requires the development of technical and managerial approaches that are 34 %C4%B1%20%C4%B0klim%20Proje/Ya%C4%9Fmur%20Suyu %20Hasad%C4%B1%20Rehber%20Dok%C3%BCman%C4%B1. pdf. Green Blue Urban. (2025). Are Sponge Cities the Future of Urban Resilience? Access Address (01.06.2025): https://greenblue.com/gb/are-sponge-cities-the-future-of-urbanresilience/. Greening Solution. (2024). Sponge Cities: Terminology, Applications, Development History, and Future Prospects in Different Countries. Global Sponge Cities: Terminology, Applications, Development, and Future Prospects. Guan, X., Wang, J. & Xiao, F. (2021). Sponge city strategy and application of pavement materials in sponge city. Journal of Cleaner Production, 303, 127022. Guo, X. (2023). Building resilient sponge communities through government interventions: exploring the role of community and stakeholder participation in sustainable economic and environmental development. AgBioForum, 25(1), 107-117. Hou, X., Guo, H., Wang, F., Li, M., Xue, X., Liu, X. & Zeng, S. (2020). Is the sponge city construction sufficiently adaptable for the future stormwater management under climate change?. Journal of Hydrology, 588, 125055. Jia, H., Wang, Z., Zhen, X., Clar, M. & Yu, S. L. (2017). China’s sponge city construction: A discussion on technical approaches. Frontiers of Environmental Science & Engineering, 11, 1-11. Jiang, D., Hua, R. & Shao, J. (2022). Ecological evaluation of sponge city landscape design based on aquatic plants application. Land, 11(11), 2081. Kabisch, N., Qureshi, S. & Haase, D. (2015). Human–environment interactions in urban green spaces - A systematic review of contemporary issues and prospects for future research. Environmental Impact assessment review, 50, 25-34. Kırmızıbayrak, E., Demircan, N. & Irmak, M. A. (2024, December). Sponge Cities in The Fight Against Climate. In SETSCI-Conference 35 Proceedings (Vol. 20, pp. 153-158). SETSCI-Conference Proceedings. Li, X., Zhang, C. & Xie, H. (2019). Evaluation of ecological benefits of sponge city construction: A case study in Shanghai. Ecological Indicators, 107, 105585. Liang, X. (2018). Integrated economic and financial analysis of China’s sponge city program for water-resilient urban development. Sustainability, 10(3), 669. Liao, K. H. (2012). A theory on urban resilience to floods—a basis for alternative planning practices. Ecology and Society, 17(4), 48. Limoncu, S. & Bayülgen, C. (2005). Türkiye’de afet sonrası yaşanan barınma sorunları. Megaron, 1(1), 18. Liu, J. & Fan, B. (2023). What contributes to local-level institutional adaptation under climate change? A configurational approach based on evidence from China's Sponge City Program. Journal of Environmental Management, 342, 118292. Luan, B., Yin, R., Xu, P., Wang, X., Yang, X., Zhang, L. & Tang, X. (2019). Evaluating green stormwater infrastructure strategies' efficiencies in a rapidly urbanizing catchment using SWMM-based TOPSIS. Journal of Cleaner Production, 223, 680-691. Ma, J., Liu, D. & Wang, Z. (2023). Sponge city construction and urban economic sustainable development: An ecological philosophical perspective. International journal of environmental research and public health, 20(3), 1694. Meral, İ. (2025). İklim değişikliğine uyum ve azaltıma yönelik stratejik yaklaşımlar: Kavramsal ve uygulamalı değerlendirmeler. Karatay Journal of Art and Design, 2(1), 34-53. Mol, A. P. & Sonnenfeld, D. A. (2014). Ecological Modernisation Around The World: Perspectives and Critical Debates. Routledge. Nguyen, T. T., Ngo, H. H., Guo, W. & Wang, X. C. (2020). A new model framework for sponge city implementation: Emerging challenges and future developments. Journal of Environmental Management, 253, 109689. 36 Nguyen, T. T., Ngo, H. H., Guo, W., Wang, X. C., Ren, N., Li, G., Ding, J. & Liang, H. (2019). Implementation of a specific urban water management-Sponge City. Science of the Total Environment, 652, 147-162. Pickett, S. T., Cadenasso, M. L. & Grove, J. M. (2004). Resilient cities: Meaning, models, and metaphor for integrating the ecological, socio-economic, and planning realms. Landscape and Urban Planning, 69(4), 369-384. Presidency of Strategy and Budget, Republic of Türkiye. (2023). 12th Development Plan (2024–2028). Access Address (07.05.2025): https://www.sbb.gov.tr/wp-content/uploads/2023/12/On-IkinciKalkinma-Plani_2024-2028_11122023.pdf. Qiao, X. J., Liao, K. H. & Randrup, T. B. (2020). Sustainable stormwater management: A qualitative case study of the Sponge Cities initiative in China. Sustainable Cities and Society, 53, 101963. Republic of Türkiye Ministry of Environment, Urbanisation and Climate Change. (2022). Climate Change Adaptation Strategy and Action Plan (2023–2027). Access Address (08.05.2025): https://iklim.gov.tr/db/turkce/icerikler/files/%C4%B0klim%20De% C4%9Fi%C5%9Fikli%C4%9Fine%20Uyum%20Stratejisi%20ve% 20Eylem%20Plan_%202024-2030.pdf. Republic of Türkiye Ministry of Environment, Urbanisation and Climate Change. (2023). Türkiye Spatial Strategy Plan – Preliminary Reports. Republic of Türkiye Ministry of Environment, Urbanization and Climate Change, Directorate of Climate Change. (2023). Updated Nationally Determined Contribution (NDC). Access Address (10.05.2025): https://www.iklim.gov.tr/db/turkce/haberler/files/T%C3%BCrkiye %20Cumhuriyeti%20G%C3%BCncellenmi%C5%9F%20Birinci% 20Ulusal%20Katk%C4%B1%20Beyan%C4%B1(1).pdf. Republic of Türkiye Ministry of Interior, Disaster and Emergency Management Authority (AFAD). (2022). Türkiye Disaster Risk Reduction Plan (TARAP). Access Address (02.04.2025): https://www.afad.gov.tr/turkiye-afet-risk-azaltma-plani-tarap. 37 Shi, Y., Li, J., Shi, T., Xiu, D. & Chu, Y. (2021, August). Research of sponge city landscape planning based on landscape security pattern. In Journal of Physics: Conference Series (Vol. 2002, No. 1, p. 012076). IOP Publishing. Sun, Y., Deng, L., Pan, S. Y., Chiang, P. C., Sable, S. S. & Shah, K. J. (2020). Integration of green and grey infrastructures for sponge city: Water and energy nexus. Water-Energy Nexus, 3, 29-40. Tu, X. & Tian, T. (2015). Six questions towards a sponge city--report on power of public policy: Sponge city and the trend of landscape architecture. Landscape Architecture Frontiers, 3(2), 22-32. Tuğaç, Ç. (2022). İklim değişikliği krizi ve şehirler. Journal of Environment, Urbanisation and Climate, 1(1), 38-60. Tunçay, H. (2022). Sünger şehirler. Environment, Climate, and Sustainability, 23(2), 99-108. Walker, L., Ashley, R., Nowell, R., Gersonius, B. & Evans, T. (2012, January). Surface water management and urban green infrastructure in the UK: A review of benefits and challenges. In International Conference on Water Sensitive Urban Design (7th: 2012: Melbourne, Vic.) (pp. 703-710). Barton, ACT: Engineers Australia. Wang, Y., Cai, J., Zuo, J., Bartsch, K. & Huang, M. (2021). Conflict or consensus? Stakeholders' willingness to participate in China's Sponge City program. Science of the Total Environment, 769, 145250. Wei, Z., Jiazhuo, W., Han, C., Chen, W., Chunyang, Z., Lian, S. & Jin, F. (2017). Experience of sponge city master plan: A case study of Nanning City. China City Planning Review, 26(3). Wong, T. H. & Brown, R. R. (2009). The water sensitive city: Principles for practice. Water Science and Technology, 60(3), 673-682. Xia, J., Zhang, Y., Xiong, L., He, S., Wang, L. & Yu, Z. (2017). Opportunities and challenges of the sponge city construction related to urban water issues in China. Science China Earth Sciences, 60, 652-658. 38 Xiang, C., Liu, J., Shao, W., Mei, C. & Zhou, J. (2019). Sponge city construction in China: Policy and implementation experiences. Water Policy, 21(1), 19-37. Yang, B., Xu, T. & Shi, L. (2017). Analysis on sustainable urban development levels and trends in China's cities. Journal of Cleaner Production, 141, 868-880. Yin, D., Xu, C., Jia, H., Yang, Y., Sun, C., Wang, Q. & Liu, S. (2022). Sponge city practices in China: From pilot exploration to systemic demonstration. Water, 14(10), 1531. Yörüklü, N. (2021). İklim değişikliği ve küresel ısınma için peyzaj mimarlığı stratejileri: İklim değişikliği politikaları peyzaj beyanı. Peyzaj, 3(1), 43-55. Yu, K., (2012), Designed Ecologies. The Landscape Architecture of Kongjian Yu. William S. Saunders. Zevenbergen, C., Fu, D. & Pathirana, A. (2018). Transitioning to sponge cities: Challenges and opportunities to address urban water problems in China. Water, 10(9), 1230. Zha, X., Luo, P., Zhu, W., Wang, S., Lyu, J., Zhou, M., ... & Wang, Z. (2021). A bibliometric analysis of the research on sponge city: Current situation and future development direction. Ecohydrology, 14(7), e2328. Zhang, Y. S. (2017). Sponge City theory and its application in landscape. World construction, 6(1), 29-33. Zhao, Z. Y., Gao, L. & Zuo, J. (2019). How national policies facilitate low carbon city development: A China study. Journal of Cleaner Production, 234, 743-754. Zhou, Q. (2014). A review of sustainable urban drainage systems considering the climate change and urbanization impacts. Water, 6(4), 976-992. Zhu, Y., Xu, C., Yin, D., Xu, J., Wu, Y. & Jia, H. (2022). Environmental and economic cost-benefit comparison of sponge city construction in different urban functional regions. Journal of Environmental Management, 304, 114230. 39 Assist. Prof. Esra KESKİN E-mail: [email protected] Educational Status: PhD. License: BSc. in Law, Gazi University, 1999-2004 Degree: MSc. in Real Estate Development and Management, Ankara University, 2010-2017 Doctorate: PhD. in Real Estate Development and Management, Ankara University, 2017-2023 Professional experiences: Assistant Professor, Ankara University, Faculty of Applied Sciences, Department of Real Estate Development and Management, 2024–present. Research Assistant, Ankara University, Faculty of Applied Sciences, Department of Real Estate Development and Management, 2019-2024 Lawyer, Çankaya Law Firm, 2005-2019 Res. Assist. Emine BAYDAN E-mail: [email protected] Educational Status: MSc., PhD. Candidate License: BSc. in Urban and Regional Planning, METU, 2007-2012 Degree: MSc. in Real Estate Development and Management, Ankara University, 2017-2021 Doctorate: PhD. in Real Estate Development and Management, Ankara University, 2021-present Professional experiences:Research Assistant, Ankara University, Faculty of Applied Sciences, Department of Real Estate Development and Management, 2018-present Urban Planner, Directorate of Gallipoli Historic Site, Çanakkale, 2015-2016